Calcineurin, which functions in calcium signaling, is expressed in skeletal and cardiac muscle and has been linked to sensitivity to muscle strength training. It is also proposed to contribute to individual aerobic endurance. To investigate the relationship between calcineurin-encoding genes and aerobic endurance traits, 126 young-adult Han Chinese males were enrolled in an aerobic exercise training study. Participants were genotyped for polymorphisms within the 5 genes (PPP3CA, PPP3CB, PPP3CC, PPP3R1 and PPP3R2) encoding calcineurin using restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) or matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Participants underwent 18 weeks of aerobic exercise training (running). Before and after the training period, maximal oxygen uptake (VO2max) and 12 km/h running economy were measured. Statistical analyses were performed using chi-square test and analysis of variance. The baseline value of VO2max was significantly associated with rs3804423 and rs2850965 loci in the PPP3CA gene (P<0.05). The training responsiveness of VO2max was significantly associated with the rs3804358 locus in PPP3CA and the rs4671887 locus in PPP3R1 (P<0.05). The training responsiveness of running economy was significantly associated with rs3739723 in PPP3R2 (P<0.05). These findings indicate that polymorphisms within the calcineurin-encoding genes may partially explain individual differences in response to aerobic training.